I have an array of 96 LEDs powered by 9v wired in the configuration below. When I measure the current draw of the entire array, I get a reading of ~190mA (my batteries are at 8v right now). The configuration below says that the LEDs should draw ~960mA. Do I need to lower the resistance to maximize the output of the LEDs? Why was the LED array wizard (or myself) inaccurate?

I am not sure where that program got its information from but 960mA looks way out.

You say your voltage is actually 8V, if the LEDs have 3.2V forward volts drop you will have a voltage of:-8 - 3.2 - 3.2 = 1.6V across the resistor.As you have a 150R resistor this gives a current of 1.6 / 150 = 10.6mAAs you have 96 LEDs you should have 10.6 * 96 = 1.024 Amps

That is a lot of a miss match between what you measure. Are you sure you are measuring it correctly?

You might be interested in this Alkaline AA Spec Sheet:http://data.energizer.com/PDFs/E91.pdf

Specifically, the graphs that show the max current out of the AA is around 300-500mA, for about an hour.

You're still drawing more current out of your batteries than they can provide, which you're seeing by the 1V drop (and lack of full current.) You need to put 6 batteries in series to get 9V and then another 6 in parallel (at least) to get the amount of current you want.